Nissan Murano Z50 (2004 year). Manual - part 98

DTC P1274, P1284 A/F SENSOR 1

EC-479

C

D

E

F

G

H

I

J

K

L

M

A

EC

Revision: 2004 November

2004 Murano

Specification data are reference values and are measured between each terminal and ground.

CAUTION:

Do not use ECM ground terminals when measuring input/output voltage. Doing so may result in dam-
age to the ECM's transistor. Use a ground other than ECM terminals, such as the ground.

Diagnostic Procedure

ABS00A6V

1. 

CHECK GROUND CONNECTIONS

1.

Turn ignition switch OFF.

2.

Loosen and retighten two ground screws on the body.
Refer to 

EC-139, "Ground Inspection"

 .

OK or NG

OK

>> GO TO 2.

NG

>> Repair or replace ground connections.

2. 

RETIGHTEN AIR FUEL RATIO (A/F) SENSOR 1

Loosen and retighten the air fuel ratio (A/F) sensor 1.

>> GO TO 3.

TERMI-

NAL 

NO.

WIRE 

COLOR

ITEM

CONDITION

DATA (DC Voltage)

57 P

A/F sensor 1 (Bank 2)

[Engine is running]

●

Warm-up condition

●

Idle speed

Approximately 2.6V

58

SB

Approximately 2.3V

76

G/Y

Approximately 3.1V

77

LG

Approximately 2.3V

PBIB1835E

Tightening torque: 40 - 60 N-m (4.1 - 6.1 kg-m, 30 - 44 ft-lb)

PBIB2291E

EC-480

DTC P1274, P1284 A/F SENSOR 1

Revision: 2004 November

2004 Murano

3. 

CLEAR THE SELF-LEARNING DATA.

 With CONSULT-II

1.

Start engine and warm it up to normal operating temperature.

2.

Select “SELF-LEARNING CONT” in “WORK SUPPORT” mode with CONSULT-II.

3.

Clear the self-learning control coefficient by touching “CLEAR”.

4.

Run engine for at least 10 minutes at idle speed.
Is the 1st trip DTC P0172 or P0175 detected?
Is it difficult to start engine?

 Without CONSULT-II

1.

Start engine and warm it up to normal operating temperature.

2.

Turn ignition switch OFF.

3.

Disconnect mass air flow sensor harness connector.

4.

Restart engine and let it idle for at least 3 seconds.

5.

Stop engine and reconnect mass air flow sensor harness con-
nector.

6.

Make sure DTC P0102 is displayed.

7.

Erase the DTC memory. Refer to 

EC-61, "HOW TO ERASE

EMISSION-RELATED DIAGNOSTIC INFORMATION"

 .

8.

Make sure DTC P0000 is displayed.

9.

Run engine for at least 10 minutes at idle speed.
Is the 1st trip DTC P0172 or P0175 detected?
Is it difficult to start engine?

Yes or No

Yes

>> Perform trouble diagnosis for DTC P0172 or P0175. Refer to 

EC-224

 .

No

>> GO TO 4.

SEF968Y

PBIB1298E

DTC P1274, P1284 A/F SENSOR 1

EC-481

C

D

E

F

G

H

I

J

K

L

M

A

EC

Revision: 2004 November

2004 Murano

4. 

CHECK HARNESS CONNECTOR

1.

Turn ignition switch OFF.

2.

Disconnect A/F sensor 1 harness connector.

3.

Check harness connector for water. 
Water should not exit.

OK or NG

OK

>> GO TO 5.

NG

>> Repair or replace harness connector.

5. 

CHECK AIR FUEL RATIO (A/F) SENSOR 1 POWER SUPPLY CIRCUIT

1.

Turn ignition switch ON.

2.

Check voltage between A/F sensor 1 terminal 3 and ground with
CONSULT-II or tester.

OK or NG

OK

>> GO TO 7.

NG

>> GO TO 6.

6. 

DETECT MALFUNCTIONING PART

Check the following.

●

Harness connectors M82, F102

●

Fuse block (J/B) connector M1

●

15A fuse

●

Harness for open or short between A/F sensor 1 and fuse

>> Repair or replace harness or connectors.

PBIB2293E

Voltage: Battery voltage

PBIB1683E

EC-482

DTC P1274, P1284 A/F SENSOR 1

Revision: 2004 November

2004 Murano

7. 

CHECK A/F SENSOR 1 INPUT SIGNAL CIRCUIT

1.

Turn ignition switch OFF.

2.

Disconnect ECM harness connector.

3.

Check harness continuity between the following terminals.
Refer to Wiring Diagram.

4.

Check harness continuity between the following terminals and ground.
Refer to Wiring Diagram.

5.

Also check harness for short to power.

OK or NG

OK

>> GO TO 8.

NG

>> Repair open circuit or short to ground or short to power in harness or connectors.

8. 

CHECK A/F SENSOR 1 HEATER

Refer to 

EC-372, "Component Inspection"

 .

OK or NG

OK

>> GO TO 9.

NG

>> Replace A/F sensor 1.

9. 

CHECK INTERMITTENT INCIDENT

Perform 

EC-130, "TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT"

 .

OK or NG

OK

>> Replace A/F sensor 1.

NG

>> Repair or replace.

Removal and Installation

ABS00A6W

AIR FUEL RATIO (A/F) SENSOR 1

Refer to 

EM-23, "EXHAUST MANIFOLD AND THREE WAY CATALYST"

 .

ECM terminal

A/F sensor 1 terminal

Bank 1

16

1

35

5

56

6

75

2

Bank 2

76

1

57

5

58

6

77

2

Continuity should exist.

Bank 1

Bank 2

ECM terminal

A/F sensor 1 terminal

ECM terminal

A/F sensor 1 terminal

16

1

76

1

35

5

57

5

56

6

58

6

75

2

77

2

Continuity should not exist.

DTC P1276, P1286 A/F SENSOR 1

EC-483

C

D

E

F

G

H

I

J

K

L

M

A

EC

Revision: 2004 November

2004 Murano

DTC P1276, P1286 A/F SENSOR 1

PFP:22693

Component Description

ABS00A6X

The A/F sensor is a planar dual-cell limit current sensor. The sensor
element of the A/F sensor is the combination of a Nernst concentra-
tion cell (sensor cell) with an oxygen-pump cell, which transports
ions. It has a heater in the element.
The sensor is capable of precise measurement   = 1, but also in the
lean and rich range. Together with its control electronics, the sensor
outputs a clear, continuous signal throughout a wide   range (0.7 <

 < air).

The exhaust gas components diffuse through the diffusion gap at the
electrode of the oxygen pump and Nernst concentration cell, where
they are brought to thermodynamic balance.

An electronic circuit controls the pump current through the oxygen-
pump cell so that the composition of the exhaust gas in the diffusion
gap remains constant at   = 1. Therefore, the A/F sensor is able to
indicate air/fuel ratio by this pumping of current. In addition, a heater
is integrated in the sensor to ensure the required operating tempera-
ture of 700 - 800

°

C (1,292 - 1,472

°

F).

CONSULT-II Reference Value in Data Monitor Mode

ABS00A6Y

Specification data are reference values.

On Board Diagnosis Logic

ABS00A6Z

To judge the malfunction, the diagnosis checks that the A/F signal computed by ECM from the air fuel ratio (A/
F) sensor 1 signal fluctuates according to fuel feedback control.

DTC Confirmation Procedure

ABS00A70

CAUTION:

Always drive vehicle at a safe speed.

NOTE:
If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
TESTING CONDITION:
Before performing the following procedure, confirm that battery voltage is more than 11V at idle.

 WITH CONSULT-II

1.

Start engine and warm it up to normal operating temperature.

2.

Select “A/F SEN1 (B1)” or “A/F SEN1 (B2)” in “DATA MONITOR” mode with CONSULT-II.

3.

Check “A/F SEN1 (B1)” or “A/F SEN1 (B2)” indication.

SEF579Z

SEF580Z

MONITOR ITEM

CONDITION

SPECIFICATION

A/F SEN1 (B1)
A/F SEN1 (B2)

●

Engine: After warming up

Maintaining engine speed at 
2,000 rpm

Fluctuates around 1.5V

DTC No.

Trouble diagnosis name

DTC detecting condition

Possible Cause

P1276
1276
(Bank 1)

Air fuel ratio (A/F) sensor 1 
circuit high voltage

●

The A/F signal computed by ECM from the A/
F sensor 1 signal is constantly approx. 1.5V.

●

Harness or connectors
(The A/F sensor 1 circuit is open or 
shorted.)

●

Air fuel ratio (A/F) sensor 1

P1286
1286
(Bank 2)

EC-484

DTC P1276, P1286 A/F SENSOR 1

Revision: 2004 November

2004 Murano

If the indication is constantly approx. 1.5V and does not fluctuates, go to 

EC-489, "Diagnostic Procedure"

 .

If the indication fluctuates around 1.5V, go to next step.

4.

Select “A/F SEN1 (B1) P1276” or “A/F SEN1 (B2) P1286” of “A/F SEN1” in “DTC WORK SUPPORT”
mode with CONSULT-II.

5.

Touch “START”.

6.

When the following conditions are met, “TESTING” will be dis-
played on the CONSULT-II screen.

If “TESTING” is not displayed after 20 seconds, retry from
step 2.

7.

Release accelerator pedal fully.

NOTE:
Never apply brake during releasing the accelerator pedal.

8.

Make sure that “TESTING” changes to “COMPLETED”.
If “TESTING” changed to “OUT OF CONDITION”, retry from
step 6.

9.

Make sure that “OK” is displayed after touching “SELF-DIAG
RESULT”.
If “NG” is displayed, go to 

EC-489, "Diagnostic Procedure"

 .

Overall Function Check

ABS00A71

Use this procedure to check the overall function of the A/F sensor 1 circuit.

 WITH GST

1.

Start engine and warm it up to normal operating temperature.

2.

Drive the vehicle at a speed of 80 km/h (50 MPH) for a few minutes in the suitable gear position.

3.

Set D position, then release the accelerator pedal fully until the vehicle speed decreases to 50 km/h (30
MPH).
NOTE:
Never apply brake during releasing the accelerator pedal.

4.

Repeat steps 2 to 3 five times.

5.

Stop the vehicle and turn ignition switch OFF.

6.

Wait at least 10 seconds and restart engine.

7.

Repeat steps 2 to 3 five times.

8.

Stop the vehicle and connect GST to the vehicle.

ENG SPEED

1,000 - 3,000 rpm

Vehicle speed

70 - 120 km/h (43 - 75 MPH)

B/FUEL SCHDL

1.0 - 8.0 msec

Selector lever

D position

SEF576Z

SEF577Z

SEF578Z

DTC P1276, P1286 A/F SENSOR 1

EC-485

C

D

E

F

G

H

I

J

K

L

M

A

EC

Revision: 2004 November

2004 Murano

9.

Make sure that no DTC is displayed.
If the DTC is displayed, go to 

EC-489, "Diagnostic Procedure"

 .

EC-486

DTC P1276, P1286 A/F SENSOR 1

Revision: 2004 November

2004 Murano

Wiring Diagram

ABS00A72

BANK 1

TBWA0692E

DTC P1276, P1286 A/F SENSOR 1

EC-487

C

D

E

F

G

H

I

J

K

L

M

A

EC

Revision: 2004 November

2004 Murano

Specification data are reference values and are measured between each terminal and ground.

CAUTION:

Do not use ECM ground terminals when measuring input/output voltage. Doing so may result in dam-
age to the ECM's transistor. Use a ground other than ECM terminals, such as the ground.

TERMI-

NAL 

NO.

WIRE 

COLOR

ITEM

CONDITION

DATA (DC Voltage)

16

LG/B

A/F sensor 1 (Bank 1)

[Engine is running]

●

Warm-up condition

●

Idle speed

Approximately 3.1V

35

O/L

Approximately 2.6V

56

BR/Y

Approximately 2.3V

75

Y/R

Approximately 2.3V

EC-488

DTC P1276, P1286 A/F SENSOR 1

Revision: 2004 November

2004 Murano

BANK 2

TBWA0693E

DTC P1276, P1286 A/F SENSOR 1

EC-489

C

D

E

F

G

H

I

J

K

L

M

A

EC

Revision: 2004 November

2004 Murano

Specification data are reference values and are measured between each terminal and ground.

CAUTION:

Do not use ECM ground terminals when measuring input/output voltage. Doing so may result in dam-
age to the ECM's transistor. Use a ground other than ECM terminals, such as the ground.

Diagnostic Procedure

ABS00A73

1. 

CHECK GROUND CONNECTIONS

1.

Turn ignition switch OFF.

2.

Loosen and retighten two ground screws on the body.
Refer to 

EC-139, "Ground Inspection"

 .

OK or NG

OK

>> GO TO 2.

NG

>> Repair or replace ground connections.

TERMI-

NAL 

NO.

WIRE 

COLOR

ITEM

CONDITION

DATA (DC Voltage)

57

P

A/F sensor 1 (Bank 2)

[Engine is running]

●

Warm-up condition

●

Idle speed

Approximately 2.6V

58

SB

Approximately 2.3V

76

G/Y

Approximately 3.1V

77

LG

Approximately 2.3V

PBIB1835E

EC-490

DTC P1276, P1286 A/F SENSOR 1

Revision: 2004 November

2004 Murano

2. 

CHECK AIR FUEL RATIO (A/F) SENSOR 1 POWER SUPPLY CIRCUIT

1.

Disconnect air fuel ratio (A/F) sensor 1 harness connector.

2.

Turn ignition switch ON.

3.

Check voltage between A/F sensor 1 terminal 3 and ground with
CONSULT-II or tester.

OK or NG

OK

>> GO TO 4.

NG

>> GO TO 3.

3. 

DETECT MALFUNCTIONING PART

Check the following.

●

Harness connectors M82, F102

●

Fuse block (J/B) connector M1

●

15A fuse

●

Harness for open or short between A/F sensor 1 and fuse

>> Repair or replace harness or connectors.

Voltage: Battery voltage

PBIB2293E

PBIB1683E

DTC P1276, P1286 A/F SENSOR 1

EC-491

C

D

E

F

G

H

I

J

K

L

M

A

EC

Revision: 2004 November

2004 Murano

4. 

CHECK A/F SENSOR 1 INPUT SIGNAL CIRCUIT

1.

Turn ignition switch OFF.

2.

Disconnect ECM harness connector.

3.

Check harness continuity between the following terminals.
Refer to Wiring Diagram.

4.

Check harness continuity between the following terminals and ground.
Refer to Wiring Diagram.

5.

Also check harness for short to power.

OK or NG

OK

>> GO TO 5.

NG

>> Repair open circuit or short to ground or short to power in harness or connectors.

5. 

CHECK INTERMITTENT INCIDENT

Perform 

EC-130, "TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT"

 .

OK or NG

OK

>> Replace A/F sensor 1.

NG

>> Repair or replace.

Removal and Installation

ABS00A74

AIR FUEL RATIO (A/F) SENSOR 1

Refer to 

EM-23, "EXHAUST MANIFOLD AND THREE WAY CATALYST"

 .

ECM terminal

A/F sensor 1 terminal

Bank 1

16

1

35

5

56

6

75

2

Bank 2

76

1

57

5

58

6

77

2

Continuity should exist.

Bank 1

Bank 2

ECM terminal

A/F sensor 1 terminal

ECM terminal

A/F sensor 1 terminal

16

1

76

1

35

5

57

5

56

6

58 6

75

2

77

2

Continuity should not exist.

EC-492

DTC P1278, P1288 A/F SENSOR 1

Revision: 2004 November

2004 Murano

DTC P1278, P1288 A/F SENSOR 1

PFP:22693

Component Description

ABS00A75

The air fuel ratio (A/F) sensor 1 is a planar dual-cell limit current sen-
sor. The sensor element of the A/F sensor 1 is the combination of a
Nernst concentration cell (sensor cell) with an oxygen-pump cell,
which transports ions. It has a heater in the element.
The sensor is capable of precise measurement   = 1, but also in the
lean and rich range. Together with its control electronics, the sensor
outputs a clear, continuous signal throughout a wide   range (0.7 <

 < air).

The exhaust gas components diffuse through the diffusion gap at the
electrode of the oxygen pump and Nernst concentration cell, where
they are brought to thermodynamic balance.

An electronic circuit controls the pump current through the oxygen-
pump cell so that the composition of the exhaust gas in the diffusion
gap remains constant at   = 1. Therefore, the A/F sensor 1 is able to
indicate air/fuel ratio by this pumping of current. In addition, a heater
is integrated in the sensor to ensure the required operating tempera-
ture of 700 - 800

°

C (1,292 - 1,472

°

F).

CONSULT-II Reference Value in Data Monitor Mode

ABS00A76

Specification data are reference values.

On Board Diagnosis Logic

ABS00A77

To judge the malfunction of A/F sensor 1, this diagnosis measures response time of the A/F signal computed
by ECM from the A/F sensor 1 signal. The time is compensated by engine operating (speed and load), fuel
feedback control constant, and the A/F sensor 1 temperature index. Judgment is based on whether the com-
pensated time (the A/F signal cycling time index) is inordinately long or not.

SEF579Z

SEF580Z

MONITOR ITEM

CONDITION

SPECIFICATION

A/F SEN1 (B1)
A/F SEN1 (B2)

●

Engine: After warming up

Maintaining engine speed at 
2,000 rpm

 Fluctuates around 1.5V

DTC No.

Trouble diagnosis name

DTC detecting condition

Possible Cause

P1278
1278
(Bank 1)

Air fuel ratio (A/F) sensor 1 
circuit slow response

●

The response (from RICH to LEAN) of the A/F 
signal computed by ECM from A/F sensor 1 
signal takes more than the specified time.

●

Harness or connectors
(The A/F sensor 1 circuit is open or 
shorted.)

●

Air fuel ratio (A/F) sensor 1

●

Air fuel ratio (A/F) sensor 1 heater

●

Fuel pressure

●

Fuel injector

●

Intake air leaks

●

Exhaust gas leaks

●

PCV

●

Mass air flow sensor

P1288
1288
(Bank 2)

DTC P1278, P1288 A/F SENSOR 1

EC-493

C

D

E

F

G

H

I

J

K

L

M

A

EC

Revision: 2004 November

2004 Murano

DTC Confirmation Procedure

ABS00A78

NOTE:
If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
TESTING CONDITION:
Before performing the following procedure, confirm that battery voltage is more than 11V at idle.

 WITH CONSULT-II

1.

Start engine and warm it up to normal operating temperature.

2.

Turn ignition switch OFF and wait at least 10 seconds.

3.

Start engine and keep the engine speed between 3,500 and 4,000 rpm for at least 1minute under no load.

4.

Let engine idle for 1 minute.

5.

Select “A/F SEN1(B1) P1278/P1279” or “A/F SEN1(B1) P1288/P1289” of “A/F SEN1” in “DTC WORK
SUPPORT” mode with CONSULT-II.

6.

Touch “START”.
If “COMPLETED” appears on CONSULT-II screen, go to step
10.
If “COMPLETED” does not appear on CONSULT-II screen, go to
the following step.

7.

After perform the following procedure, “TESTING” will be dis-
played on the CONSULT-II screen.

a.

Increase the engine speed up to 4,000 to 5,000 rpm and keep it
for 10 seconds.

b.

Fully release accelerator pedal and then let engine idle for about
10 seconds.
If “TESTING” is not displayed after 10 seconds, refer to 

EC-

126, "TROUBLE DIAGNOSIS - SPECIFICATION VALUE"

 .

8.

Wait for about 20 seconds at idle at under the condition that
“TESTING” is displayed on the CONSULT-II screen.

9.

Make sure that “TESTING” changes to “COMPLETED”.
If “TESTING” changed to “OUT OF CONDITION”, refer to

EC-126, "TROUBLE DIAGNOSIS - SPECIFICATION VALUE"

 . 

10. Make sure that “OK” is displayed after touching “SELF-DIAG

RESULT”.
If “NG” is displayed, go to 

EC-498, "Diagnostic Procedure"

 .

PBIB0756E

PBIB1925E

PBIB0758E

EC-494

DTC P1278, P1288 A/F SENSOR 1

Revision: 2004 November

2004 Murano

 WITH GST

1.

Start engine and warm it up to normal operating temperature.

2.

Select “MODE 1” with GST.

3.

Calculate the total value of “Short term fuel trim” and “Long term fuel trim” indications.
Make sure that the total percentage should be within 

±

15%.

If OK, go to the following step.
If NG, check the following.

●

Intake air leaks

●

Exhaust gas leaks

●

Incorrect fuel pressure

●

Lack of fuel

●

Fuel injector

●

Incorrect PCV hose connection

●

PCV valve

●

Mass air flow sensor

4.

Turn ignition switch OFF and wait at least 10 seconds.

5.

Start engine and keep the engine speed between 3,500 and 4,000 rpm for at least 1minute under no load.

6.

Let engine idle for 1 minute.

7.

Increase the engine speed up to 4,000 to 5,000 rpm and keep it for 10 seconds.

8.

Fully release accelerator pedal and then let engine idle for about 1 minute.

9.

Select “MODE 7” with GST.
If 1st trip DTC is detected, go to 

EC-498, "Diagnostic Procedure"

 .